The present invention relates to systems for providing directory assistance services, and more particularly relates to the provision of directory assistance services in a network using out-of-band signaling.
Telephone directory assistance services have been available for the past century. While improvements have been made over the decades, such systems are still poorly suited for use by subscribers of wireless telephone services.
In prior art directory assistance services, a customer dials an operator and identifies the name and address of a party whose telephone number is desired. The operator then locates the number using printed directories or a computer database, and provides the number to the customer. (The provision of the number is sometimes done by the live operator, but more typically is done with a computerized voice response unit that provides connection to the operator is terminated.
While satisfactory for most customers, this arrangement is ill-suited for many wireless telephone customers. For one, such customers are usually away from their general work environments (e.g. in a vehicle), and thus may not have ready access to a pencil and paper in order to make a note of the desired number. (Even if such materials are available, the customer may not find it convenient to interrupt other activities, e.g. driving, in order to make a note.) In addition, the process of initiating a second callxe2x80x94to the desired partyxe2x80x94entails further manual operations (e.g. hanging up, waiting for another dial tone, and dialing) which may be a hindrance to the customer""s other activities.
The present assignee, in the prior art, has redressed certain of these difficulties by providing a directory assistance service that eliminates the need to make a note of the desired number, or undertake a redialing exercise. Instead, after determining the telephone number desired by the customer, rather than voicing it to the customer, the directory assistance operator goes ahead and initiates a call to the desired party, and connects the new outgoing call to the original customer. (The operator may stay on the line as a conferenced party so as to provide further assistance, or may withdraw from the connection, depending on the particular implementation.) This arrangement obviates the need for the customer to make a note of the voiced number, or to undertake a redialing exercise. However, if the initiated call is not completed (e.g. a xe2x80x9cbusyxe2x80x9d tone is received), or if the customer desires further directory assistance, then the customer must again call the directory assistance operator for help.
The problems associated with providing directory assistance services to wireless customers are not limited to hardships on the customers; the directory assistance service and the wireless carrier also confront unique issues. In the assignee""s prior art system, for example, the wireless carrier (which is typically responsible for billing of the customer) knows only that the customer has dialed the directory assistance operator, but does not know the number to which the customer is ultimately connected by the operator. Billing is thereby complicated. In the prior art system, the toll charges (assuming toll calls are permitted; often they are not) for the connection between the customer and the desired number are simply absorbed by the directory assistance service, and recouped by billing the wireless carrier a sufficiently large flat rate charge for each directory assistance call so as to cover these costs. The wireless carrier then bills the subscriber a fixed amount for each directory assistance inquiry, regardless of the toll charges of any further connection established for the customer by the directory assistance operator. This arrangement, however, has a number of disadvantages. In addition to increased cost, it also fails to provide the wireless carrier useful information about its customers"" calling patterns, which may affect decisions relating to system expansion, etc.
The directory assistance method disclosed herein overcomes these problems of the prior art. For example, in one embodiment of the present invention, a customer who wishes directory assistance services is connected in the conventional manner to an operator who determines the destination telephone number desired by the customer. As in the prior art, the operator then initiates a call connecting the customer to the destination telephone number. However, rather than dropping all further involvement with the call, this embodiment is capable of detecting a command to reconnect to an operator issued by the customer, such as that obtained by pressing the xe2x80x9c*xe2x80x9d button or some other button. If such a signal is detected, the customer is transferred to a directory assistance operator, who can then provide whatever further assistance is needed (e.g. redialing a busy number, or providing further directory assistance). By this arrangement, the press of a single button by the customer summons further directory assistance, rather than the redialing procedure required by the prior art.
To achieve this type of customer-driven functionality, the present invention is responsive to commands issued by the customer, for example by pressing a key on the telephone. The commands can be detected at the directory assistance switch by a DTMF receiver, or alternatively, may appear at the directory assistance service center as out-of-band signals on an associated signaling channel, independent of the actual voice channel.
Out-of-band signaling, as is well-known in the art, involves separating the voice and signaling components of a call into two separate components. The signaling information is transmitted on a signaling data link, and the voice and data traffic components are transmitted over a voice trunk. A signaling data link is a two-directional transmission path (a typical carrier channel) for signaling, comprising transmit and receive data channels operating together in opposite directions at the same data rate. The signaling information typically contains connection-oriented signaling such as address information for call setup, supervision/call control signaling, tear down, information needed for distributed application processing and network management information.
Signaling data is typically transmitted in packets between network nodes in what is known as a Common Channel Signaling (xe2x80x9cCCSxe2x80x9d) system. One example of a standardized, general-purpose protocol for a CCS system is Signaling System 7, or xe2x80x9cSS7.xe2x80x9d SS7 is an open-architecture protocol that handles current communication requirements and accommodates future expansion of new applications. It is optimized for operation in a digital telecommunications network in conjunction with stored program control switches. SS7 meets present and future requirements for information transfer (circuit and non-circuit related) for interprocessor transactions within telecommunication networks for call control, network database access, and management and maintenance signaling. Furthermore, SS7 provides a reliable means of information transfer, correctly sequenced, without loss or duplication.
The SS7 standard for telecommunications is global, defined by the International Telecommunication Union (ITU) Telecommunication Standardization Sector (ITU-T). The standard defines the procedures and protocol by which network elements in the public switched telephone network (PSTN) exchange information over a digital signaling network. The ITU definition of SS7 is designed to allow for national variants, such as the American National Standard Institute (ANSI) and Bell Communications Research (Bellcore) standards used in North America, and the European Telecommunications Standards Institute (ETSI) standard used in Europe. The naming conventions have been defined as follows: CCITT SS#7 indicates International Signaling system 7, and SS7 indicates the U.S. version of Signaling System 7. SS7 has been appropriately modified for use with and between U.S. networks. SS7 is intended to be generally compatible with CCITT SS#7.
SS7 transport has become the primary mode for signaling and information transfer in today""s wireless and wireline networks. Information elements like calling party number, routing information related to 800 numbers, and current location information for roaming wireless subscriber are all carried over SS7 signaling networks. SS7 makes features such as call waiting, three-way calling and caller ID possible. The benefits of the SS7 protocol include more efficient call processing, AIN products and services (Advanced Intelligent Network: service-independent capabilities used in SS7 to support advanced features), better reliability, faster call processing, faster call set up and tear down, and more accurate signaling detection. With SS7, regular voice lines are not tied up until the call is actually established or the destination number has been identified as available (through the signaling data link)xe2x80x94about 40% of all calls made are not completed because of either a busy signal or no answer.
SS7 call processing provides great flexibility in receiving and/or responding to customer-issued commands. For example, in one embodiment of the present invention a customer can issue a command for conferencing by pushing a key on the customer""s phone (e.g. the xe2x80x9c*xe2x80x9d key), which is detected at the directory assistance service center as an SS7 message. Then, either a directory assistance operator or an automated system determines the telephone number of an additional party the customer wishes to conference in, and a telephonic connection between the additional party and the existing connection is initiated using SS7 call processing. The operator or automated system can continue to add additional parties or delete parties as desired by the customer using SS7 call processing, or the customer can reinitiate the procedure at a later time to further change the participating parties.
Alternatively, the command for conferencing by the customer could be detected by a DTMF tone receiver on the voice channel, while call initiation and processing occurs through SS7 signaling.
In another embodiment of the present invention, the directory assistance center, in attempting to initiate a telephonic connection between the customer and the customer""s desired customer, takes certain actions upon detection of a SS7 signaling message indicting connection problems (such as ring-no-answer or call could not be completed). The actions include either directly reconnecting the customer, or offering the customer a variety of automated menu options, including returning to an operator.
In yet another embodiment, upon receiving a call from a customer at the directory assistance service, a preferred service associated with that customer is determined from a customer attribute database, or in the event the customer does not have an associated preferred service, a default service chosen. Upon detection of a SS7 signaling message or DTMF tone indicating the customer has issued a command for the preferred service, the directory assistance service center actuates the preferred service using SS7 call processing, whether it be reconnecting to an operator, conferencing in other parties, or any other of a variety of enhanced directory assistance features.
The directory assistance system disclosed herein further addresses the billing difficulties associated with completion of customer calls by directory assistance operators. In one embodiment of the invention, the directory assistance service logs, in a billing database, information identifying the customer (i.e. the customer identification number accompanying the call from the wireless provider), the destination number to which the customer is connected, and the date, time and duration of the customer/destination number connection. This log of information is periodically provided to the wireless carrier, allowing it to bill the customer for the call connected by the directory assistance operator and recoup the associated expense. This permits the flat rate charged by the directory assistance provider to be reduced correspondingly, and provides the wireless service with more detailed information about its customers"" usage requirements.
The foregoing and additional features and advantages of the present invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.